Novel synthesis of liquid crystalline phthalocyanines

Full text of DOI:10.1021/jo9919254

J . Org. Chem. 2000, 65, 2257-2260
2257
Sch em e 1. Syn th esis of Alk oxy P h th a locya n in esa
Novel Syn th esis of Liqu id Cr ysta llin e
P h th a locya n in es
Anthony S. Drager and David F. O’Brien*
C. S. Marvel Laboratories, Department of Chemistry,
University of Arizona, Tucson, Arizona 85721
Received December 16, 1999
In tr od u ction
The physical and chemical properties of phthalocya-
nines (Pc) have long attracted considerable interest due
to their applications as dyes, organoelectronics, liquid
crystals, ultrathin films, and in photodynamic therapy.1
A particularly attractive feature of Pc is the dependence
of the properties of the molecule on the nature of the
peripheral functional groups, as well as the electronic
properties of the central metal cations in the phthalo-
cyanine ring.2 Unsubstituted phthalocyanines are not
very soluble and tend to aggregate in solution; however,
the addition of peripheral chains can increase solubility,
processibility, and facilitate the formation of discotic
mesophases.3 Indeed we recently reported copper(II)
2,3,9,10,16,17,23,24-octakis(2-benzyoxyethoxy)phthalo-
cyanine (1) (see Scheme 1) exhibits an exceptionally
stable discotic mesophases.4 Moreover, the unusual de-
gree of cofacial association of this Pc favors the formation
of coherent self-associated rodlike structures at the air-
water interface and after transfer onto solid supports.5
The highly ordered thin films of 1 exhibit large electrical
and optical anisotropies.6 Consequently we have devel-
oped an improved synthetic method to prepare this class
of Pc.
Despite the active research on substituted Pc, the
methods of synthesis have changed relatively little in the
last 90 years.7,8 Metal-free and non-copper metallo-Pc are
typically prepared from the corresponding phthalonitriles
(Scheme 1), which are often synthesized from the corre-
sponding substituted 1,2-dibromo benzenes, utilizing
copper(I) cyanide in the Rosenmund-von Braun reaction.
The reaction involves refluxing the dibromobenzene with
the CuCN in dimethylformamide, substituting nitriles for
the bromides via a complex mechanism.9 The conditions
of the Rosenmund-von Braun reaction are a suitable
route to copper-substituted phthalocyanines, since the
phthalonitrile tetramerizes directly to the phthalocyanine
under the reaction conditions. However if non-copper
metallo-Pc are desired, the formation of copper phthalo-
a
Key: (a) pentanol, DBU, heat, and MX2 in the case of 1 and
2 (MX2 ) CuBr2 for 1/CoBr2 for 2).
cyanine results in undesirable low yields of the desired
phthalonitrile and complex product mixtures, which can
be difficult to purify.10 Accordingly a more general
synthetic approach to the phthalonitrile precursors were
sought that would allow the ready synthesis of extremely
pure phthalocyanines with diverse functionality and
substitution. We have developed a new synthetic method
for the synthesis of substituted phthalonitriles from
readily available starting materials with an excellent
overall yield of 45% after eight steps. In addition this
method is suitable for scale-up to produce multigram
quantities, because purification required only one chro-
matography step.
Resu lts a n d Discu ssion
Syn th etic Design . The production of substituted
phthalocyanines for various areas of research is con-
trolled by the synthesis of the corresponding phthaloni-
trile precursors. We turned to the well characterized
Diels-Alder reaction to produce the key intermediate for
subsequent conversion to the desired phthalonitrile. The
Diels-Alder approach provides maximum flexibility in
a general synthetic approach to Pc, because it is possible
to place a variety of substituents on the phthalonitrile,
without the possibility of side products that can occur in
the Rosenmund-von Braun reaction.11
Syn th esis of th e Ar om a tic Cor e. Synthesis of 4,5-
bis(benzyloxyethoxy)phthalic acid dimethyl ester (10)
began with the commercially available 2,3-butadione (4),
which was converted by the method of Hansson12 to 2,3-
bis(trimethylsilyloxy)-1,3-butadiene (5) using LiBr, tri-
methyl silyl chloride (TMS-Cl), and triethylamine (Scheme
2). The desired substituted butadiene 5 was collected by
vacuum distillation (86%). A Diels-Alder cycloaddition
between the commercially available dimethylacetylene
dicarboxylate (6) and the butadiene 5 was performed neat
at 90 °C for 24 h.13 The desired cyclohexadiene (7) was
purified by vacuum distillation (83%). The cyclohexadiene
7 was aromatized with cleavage of the TMS groups by
treatment with bromine in CCl4, and the desired product
(8) precipitated and was collected by filtration with
excellent yield (94%). The alkoxy “arms” were attached
(1) Hanack, M.; Heckmann, H.; Polley, R. In Methods of Organic
Chemistry, 4th ed.; Schaumann, E., Ed.; Georg Thieme Verlag:
Stuttgart, 1998; Vol. E-9, pp 717-843.
(2) Osburn, E. J .; Chau, L.-K.; Chen, S.-Y.; Collins, N.; O’Brien, D.
F.; Armstrong, N. R. Langmuir 1996, 12, 4784.
(3) Piechocki, C.; Simon, J .; Skoulios, A.; Guillon, D.; Weber, P. J .
Am. Chem. Soc. 1982, 104, 5245.
(4) Osburn, E. J .; Schmidt, A.; Chau, L.-K.; Chen, S.-Y.; Smolenyak,
P.; Armstrong, N. R.; O’Brien, D. F. Adv. Mater. 1996, 8, 926.
(5) Smolenyak, P. E.; Osburn, E. J .; Chen, S. Y.; Chau, L. K.;
O’Brien, D. F.; Armstrong, N. R. Langmuir 1997, 13, 6568.
(6) Smolenyak, P.; Peterson, R.; Nebesny, K.; To¨rker, M.; O’Brien,
D. F.; Armstrong, N. R. J . Am. Chem. Soc. 1999, 121, 8628.
(7) Braun, A.; Tcherniac, J . Ber. Dtsch. Chem. Ges. 1907, 40, 2709.
(8) de Diesbach, H.; von der Weid, E. Helv. Chim. Acta 1927, 10,
886.
(10) Ito, T.; Watanabe, K. Bull. Chem. Soc. J pn. 1968, 41, 419.
(11) Conner, J . A.; Leeming, S. W.; Price, R. J . Chem. Soc., Perkin.
Trans. 1 1990, 1127.
(12) Hansson, L.; Carlson, R. Acta Chem. Scand. 1989, 43, 304.
(13) Reetz, M.; Neumeier, G. Chem. Ber. 1979, 112, 2209.
(9) Couture, C.; Paine, A. J . Can J . Chem. 1985, 63, 111.
10.1021/jo9919254 CCC: $19.00 © 2000 American Chemical Society
Published on Web 03/08/2000

2258 J . Org. Chem., Vol. 65, No. 7, 2000
Notes
Sch em e 2. Syn th esis of Ar om a tic Cor ea
white precipitate was collected by vacuum filtration,
washed with DI water, and dried in a vacuum desiccator
for 12 h, yielding a light tan solid (96%). The phthalamide
(13) was dehydrated to the phthalonitrile (14) using an
oxalyl chloride/DMF complex at 0 °C in 45 min. The
phthalonitrile was collected nearly quantitatively (93%)
by extraction into ethyl ether and concentration in vacuo.
The slightly yellow liquid crystallized without further
need for purification, to yield the desired product as white
crystalline needles that showed no contaminants by NMR
or TLC.
The Diels-Alder route to the phthalonitrile is more
efficient and flexible than previous methods. We have
shown that the Diels-Alder method for the synthesis of
an alkoxy-substituted phthalonitrile occurs in 45% over-
all yield, compared to 24% yield14 when using the
Rosenmund-von Braun reaction. Typical yields of other
alkoxy-substituted phthalonitriles when synthesized us-
ing the Cu(I)CN reagent are 22-33%.15,16 Moreover, this
new method allows the synthesis of very pure phthaloni-
trile precursors without the possibility of metal contami-
nation or rearrangements.
a
Key: (a) TMSCl, LiBr, triethylamine, THF; (b) 90 °C; (c) 5%
Br2/CCl4; (d) benzyloxyethoxy bromide (9), K2CO3, acetone.
Sch em e 3. Con ver sion to P h th a lon itr ilea
The potential generality of the Diels-Alder method is
illustrated by consideration of other dienes that are
known to react with the dimethylacetylene dicarboxylate
(DMAD) dieneophile. These reports indicate that a
phthalonitrile precursor to Pc could be prepared with
alkyl groups,17,18 alkyl halides,19 alkyl nitro compounds,20
alkyl carboxylic acids,21 amines,22 silyl compounds,23-26
alkenes,27 thioethers,28 unsymmetrically substituted sys-
tems,29,30 and external ring systems.31 It has been shown
that DMAD will also under go cycloaddition with the
appropriate dienes to offer a possible synthetic route to
substituted naphthalocyanines32 and azaphthalo-
cyanines.33-35 In theory this chemistry could be modified
to incorporate electron-withdrawing substituents on the
a
Key: (a) (1) 10% NaOH, EtOH, (2) 10% HCl (b) urea; (c) 30%
NH4OH; (d) oxalyl chloride/DMF, pyridine.
using a Williamson ether synthesis between the com-
mercially available 2-benzyloxy-1-ethyl bromide (9) and
the catechol phthalic acid dimethyl ester (8) by refluxing
in acetone with K2CO3 as the base. The reaction was
purified by gravity filtration to remove insoluble salts,
and the solvent was removed in vacuo to yield a pale
yellow oil. The oil was purified by column chromatogra-
phy to yield the desired ether (10) as a white solid upon
removal of the solvent (90%).
(14) Osburn, E. J . Ph.D. Thesis, University of Arizona, 1995.
(15) Toupance, T.; Pierre, B.; Mineau, L.; Simon, J . J . Phys. Chem.
1996, 100, 11704.
(16) van der Pol, J . F.; Neeleman, E.; van Miltenburg, J . C.; Zwikker,
J . W.; Nolte, R. J . M.; Drenth, W. Macromolecules 1990, 23, 155.
(17) Angus, J . R. O.; J ohnson, R. P. J . Org. Chem. 1983, 48, 273.
(18) Weber, G.; Menke, K.; Hopfi, H. Chem. Ber. 1980, 113, 531.
(19) Hegedus, L. S.; Kambe, N.; Ishii, Y.; Mori, A. J . Org. Chem.
1985, 50, 2240.
(20) Kozikowski, A. P.; Hiraga, K.; Springer, J . P.; Wang, B. C.; Xu,
Z.-B. J . Am. Chem. Soc. 1984, 106, 1845.
Con ver sion of th e Diester to P h th a lon itr ile. Con-
version of the alkoxy-substituted phthalic ester (10)
(Scheme 3) into the phthalonitrile began with the sa-
ponification of the ester by heating in aqueous sodium
hydroxide/methanol for 12 h, upon which the solution was
concentrated in vacuo to remove methanol. The pH of the
solution was lowered to 3.0 using 10% HCl, and a white
precipitate formed. The sample was cooled to 5 °C, and
the resulting solid was filtered to yield the desired
phthalic acid (11) as white crystals (99%). The conversion
of the phthalic acid (11) to the corresponding phthalimide
(12) was achieved by heating 11 and urea to 180 °C with
evolution of ammonia and water as side products. The
reaction progress was monitored with pH paper and upon
cessation of ammonia generation the reaction was cooled
to room temperature. The resulting solid was isolated by
an aqueous workup yielding the desired phthalimide (12)
as a white solid (85%). The phthalimide (12) was con-
verted to the phthalamide (13) by stirring vigorously with
concentrated aqueous ammonia for 24 h. The resulting
(21) Grieco, P. A.; Yoshida, K.; Garner, P. J . Org. Chem. 1983, 48,
3137.
(22) Oppolzer, W.; Bieber, L.; Francotte, E. Tetrahedron Lett. 1979,
4537.
(23) Hosomi, A.; Saito, M.; Sakurai, H. Tetrahedron Lett. 1980, 21,
355.
(24) Sakurai, H.; Hosomi, A.; Saito, M.; Sasaki, K.; Iguchi, H.;
Sasaki, J .-L.; Araki, Y. Tetrahedron 1983, 39, 883.
(25) Batt, D. G.; Ganem, B. Tetrahedron Lett. 1978, 3323.
(26) Chou, T.; Tso, H. H.; Tao, Y. T.; Lin, L. C. J . Org. Chem. 1987,
52, 244.
(27) Kanemasa, S.; Sakoh, H.; Wada, E.; Tsuge, O. Bull. Chem. Soc.
J pn. 1986, 59, 1869.
(28) Garst, M. E.; Arrhenius, P. Synth. Commun. 1981, 11, 481.
(29) Danishefsky, S.; Kitahara, T.; Yan, L. F.; Morris, J . J . Am.
Chem. Soc. 1979, 101, 6996.
(30) Dowd, P.; Weber, W. J . Org. Chem. 1982, 47, 4774.
(31) Bodalsky, R.; Koszuk, J .; Krawczyk, H.; Pietrusiewicz, K. M.
J . Org. Chem. 1982, 47, 2219.
(32) Ihara, M.; Ishida, Y.; Fukumoto, K.; Kametani, T. Chem.
Pharm. Bull. 1985, 33, 4102.
(33) Mazumdar, S. N.; Sharma, M.; Mahajan, M. P. Tetrahedron
Lett. 1987, 28, 2641.
(34) Boger, D. L. Tetrahedron 1983, 39, 2869.
(35) Cheng, Y.-S.; Ho, E.; Mariano, P. S.; Ammon, H. L. J . Org.
Chem. 1985, 50, 5678.

Notes
J . Org. Chem., Vol. 65, No. 7, 2000 2259
spectrometry. Phthalic acid 11 (2.53 g, 4.93 mmol) was heated
to 180 °C with constant stirring in a 50 mL beaker containing
urea (0.65 g, 10.8 mmol). The reaction was removed from the
oil bath when the evolution of ammonia gas ceased, as monitored
using moistened pH paper. The resulting solid was dissolved in
CH2Cl2/DI water, and the organic layer was separated and dried
over MgSO4. Removal of the CH2Cl2 in vacuo afforded 1.87 g of
the desired phthalimide (12) (85%) as a white solid: mp 129-
130 °C, R×a6 ) 0.92 (90:10 CHCl3/MeOH), IR (KBr) 3250, 1767,
and 1711 cm-1, 1H NMR (CD2Cl2) δ 7.55-7.39 (broad, 1H), 7.35-
7.12 (m, 12H), 4.54 (s, 4H), 4.22 (t, J ) 4.6 Hz, 4H) and 3.83 (t,
J ) 4.6 Hz, 4H), 13C NMR (CD2Cl2) δ 168.2, 154.1, 138.5, 128.7,
128.03, 127.96, 126.5, 107.2, 73.6, 69.6, and 68.5, Mass Spectral
Analysis (ESI) MI 448.2 (MH+).
4,5-Bis(ben zyloxyeth oxy)p h th a la m id e (13). The conver-
sion of the phthalimide (12) to the phthalamide (13) was
achieved by modification of a literature procedure.37 A mixture
of phthalimide 12 (1.53 g, 3.4 mmol) and 40 mL of 25% (wt %)
aqueous ammonia in a 50 mL round-bottom flask was sealed
with a rubber septum and stirred vigorously for 24 h at room
temperature. The mixture was then gravity filtered and washed
with DI water. The solid collected was dried in a vacuum
desiccator for 12 h, affording 1.53 g of the desired phthalamide
13 (96%) as a light tan solid. mp ) 161-163 °C, R×a6 ) 0.30
(90:10 CHCl3/MeOH), IR (KBr) 3387, 3195, 1653, 1597 cm-1, 1H
(DMSO-d6) δ 7.85-7.72 (broad, 4H), 7.44-7.22 (m, 12H), 4.63
(s, 4H), 4.29 (t, J ) 4.6 Hz, 4H), 3.86 (t, J ) 4.6 Hz, 4H), 13C
NMR (d6-DMSO) δ 169.7, 149.5, 138.4, 129.1, 129.1, 128.2,
127.51, 127.48, 113.5, 72.1, 68.4, 68.0, mass spectral analysis
(FAB) MI 465.11 (MH+).
diene utilizing an “inverse demand” Diels-Alder reaction;
however, this subject will be left for future investigations.
Exp er im en ta l Section
Gen er a l In for m a tion . All nonaqueous reactions were car-
ried out under an argon atmosphere unless otherwise specified.
Reagents and solvents were purchased from Aldrich Chemical
and used as received unless otherwise specified. THF was
distilled from Na/benzophenone. LiBr was dried for 24 h in a
vacuum oven at 200 °C. 2,3-bis(trimethylsilyloxy)-1,3-butadiene
(5) was prepared as described by Hansson12 in 86% yield.
1,2-Bis(tr im eth ylsilyloxy)-1,4-cycloh exa d ien e-4,5-d ica r -
boxylic Acid Dim eth yl Ester (7).13 A mixture of bis(trimeth-
ylsilyloxy)-1,3-butadiene (5) (15.62 g, 67.8 mmol) and acetylene-
dicarboxylic acid dimethyl ester (6) (10.60 g, 74.6 mmol) was
stirred 24 h at 90 °C. Vacuum distillation of the mixture gave
20.87 g of the product, bp 133-138 °C, 0.1 mmHg (82.6% yield).
1H NMR (CDCl3): δ 3.72 (s, 6H), 3.05 (s, 4H), 0.18 (s, 18H). 13C
NMR (CDCl3): δ 167.52, 132.07, 127.48, 52.28, 32.82, 0.75. Mass
spectral analysis (GC/MS): MI peak ) 372 (M+), 339, 251, 193,
73, 45.
4,5-Bis(h yd r oxy)p h th a lic Acid Dim eth yl Ester (8). A 5%
(wt/wt) solution of Br2 in carbon tetrachloride was slowly added
to a solution of dimethyl ester catechol 7 (20.87 g, 56.0 mmol)
in 60 mL of CCl4 cooled to 0 °C, and it was stirred until the
reaction color remained orange. The reaction mixture was then
heated to 60 °C for 2 h, and it was then removed from heat and
cooled to 5 °C to precipitate the product. The crystals were
vacuum collected, washed with cold CCl4, and allowed to dry.
The resulting solid weighed 11.96 g (94.4% yield). The product
was identified by 1H NMR (acetone-d6): δ 3.78 (s, 6H), 7.18 (s,
2H), 8.18 (b, 2H). 13C NMR (acetone-d6): δ 168.16, 147.95,
125.55, 116.66, 52.43. Mass spectral analysis (DIP-EI): m/z )
226 (M+), 195, 179, 165,152, 136, 108, 82, 62.
4,5-Bis(ben zyloxyeth oxy)p h th a lic Acid Dim eth yl Ester
(10). A solution of dimethyl ester 8 (1.50 g, 6.63 mmol),
2-bromoethylbenzyl ether (9) (5.00 g, 23.2 mmol), and anhydrous
K2CO3 (6.00 g, 43.4 mmol) in 50 mL of acetone was refluxed for
48 h and then gravity filtered to remove unreacted K2CO3 and
KBr. The filtrate was concentrated in vacuo and purified by flash
chromatography on SiO2 eluting with hexanes/ethyl acetate (70:
30), giving the desired diether 10 (2.94 g 90%) as a white solid
upon removal of solvent: mp ) 44-46 °C, R×a6 ) 0.42 (70:30
Hex/EtOAc), IR (KBr) 1732 cm-1, 1H NMR (acetone-d6) δ 7.38-
7.17 (m, 12H), 4.57 (s, 4H), 4.29 (t, J ) 4.6 Hz, 4H), 3.88-3.75
(singlet on triplet, J ) 4.6 Hz, 10H), 13C NMR (acetone-d6) δ
168.0, 151.5, 139.6, 129.0, 128.3, 128.1, 126.4, 114.7, 73.5, 69.9,
69.2, 52.6, mass spectral analysis (FAB) MI 495.15 (theoretical
mass for C28H31O8 ) 495.20).
4,5-Bis(b en zyloxyet h oxy)p h t h a lon it r ile
(14).
The
phthalamide was converted to the phthalonitrile functionality
by using an oxalyl chloride/DMF complex.38 Anhydrous DMF
(1.20 mL, 15.5 mmol) was added via syringe to 25 mL of
acetonitrile cooled to 0 °C, and then oxalyl chloride (1.25 mL,
14.2 mmol) was slowly added with formation of a white precipi-
tate and gas evolution. When the evolution of gas ceased,
phthalamide 13 (1.50 g, 3.23 mmol) was added as a suspension
in 5 mL of acetonitrile. Within a few minutes the reaction
solution became homogeneous. Pyridine (2.30 mL, 28.4 mmol)
was then added, and the reaction was stirred for an additional
45 min at 0 °C. The reaction was then quenched by the addition
of 50 mL of ethyl ether and 50 mL of 10% HCl. The aqueous
layer was extracted and washed with 50 mL of ethyl ether. The
combined ether layers were then extracted with saturated NaCl
and dried over Na2SO4. The ether was removed in vacuo to yield
a pale yellow oil, which solidified into white needle crystals. The
resulting crystals were washed with 5 mL portions of cold
pentane and dried in a vacuum desiccator. The desired phtha-
lonitrile 14 weighed 1.30 g (93%): mp ) 77-79 °C, R×a6 ) 0.92
(90:10 CHCl3/MeOH), IR (KBr) 2228 cm-1 1H NMR (acetone-
,
d6) δ 7.64-7.58 (s, 2H), 7.41-7.17 (m, 10H), 4.63 (s, 4H), 4.44
(t, J ) 4.5 Hz, 4H) 3.92 (t, J ) 4.5 Hz, 4H), 13C NMR (acetone-
d6) δ 153.2, 139.4, 129.0, 128.3, 128.2, 117.9, 116.7, 109.0, 73.5,
70.2, 68.9, mass spectral analysis (FAB) MI 429.2 (MH+).
4,5-Bis(ben zyloxyeth oxy)p h th a lic Acid (11). A solution of
dimethyl ester 10 (2.75 g, 5.6 mmol) in 50 mL of 10% NaOH
and 50 mL methanol was heated to reflux for 24 h and then
allowed to cool to room temperature. The solution was then
concentrated in vacuo removing the methanol and a majority of
the water. A 20 mL portion of DI water was added, and the pH
of the solution was slowly adjusted to 3.0 using 10% HCl. The
solution was cooled to 5 °C, and the desired phthalic acid 11
was collected by vacuum filtration and dried for 12 h in a vacuum
oven at 60 °C. The white crystalline solid collected weighed 2.55
g (99%). mp ) 97-99 °C, IR (KBr) 2612 and 1714 cm-1, 1H NMR
(CD2Cl2) δ 12.4-11.7 (broad, 2 H), 7.55-7.14 (m, 12H), 4.57 (s,
4H), 4.12 (t, J ) 4.6 Hz, 4H) 3.74 (t, J ) 4.6 Hz, 4H), 13C NMR
(d6 DMSO) δ 168.3, 149.4, 138.4, 128.3, 127.54, 127.48, 127.11,
114.7, 72.2, 68.41, 68.12, mass spectral analysis (ESI+) MI 466.8
(theoretical mass for C26H26O8 ) 466.2).
Syn t h esis of 2,3,9,10,16,17,23,24-Oct a (2-b en zyloxyet h -
oxy)p h th a locya n in es (1-3). A solution of phthalonitrile 14
(1.00 mmol) and 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU) (1.00
mmol) in 20 mL of 1-pentanol was heated to reflux for 22 h. In
the case of the cobalt Pc (2) and copper Pc (1), 0.25 mmol of
corresponding metal(II) bromide was added as well. The result-
ing dark green solution was placed in a freezer to precipitate
the desired phthalocyanine. The solid was collected by vacuum
filtration through a medium sintered glass crucible and washed
with DI water. The solid was purified by flash chromatography
on SiO2 eluting with chloroform/methanol (99:1). Phthalocyanine
3 was obtained as a green solid (28% yield) after removal of
solvent in vacuo. R×a6 ) 0.82 (95:5 CHCl3/MeOH), IR (KBr) 3465,
2870, 1279, 1190, 1100, 1026, and 741 cm-1, UV-vis (CHCl3)
699.2, 661.3, and 598.9 nm, high-resolution mass spectral
4,5-Bis(ben zyloxyeth oxy)p h th a lim id e (12). The procedure
for phthalimide formation was modified from
a literature
method,36 and it should be noted that when the reaction in the
literature was followed using ethylene glycol as the solvent, the
n-ethanol-substituted phthalimide, not the phthalimide, was
obtained as the major product as shown by NMR and mass
analysis (FAB) MI 1715.71 (calcd mass for
C104H99N8O16
)1715.72). Cobalt phthalocyanine 2 was obtained as a green-
(37) Mikhalenko, S.; Barkanova, S.; Lebedev, O.; Luk’yanets, E. Zh.
Obshch. Khim. 1971, 41, 2735.
(38) Bargar, T.; Riley, C. Synth. Commun. 1980, 10, 479.
(36) Crockett, G.; Swanson, B.; Anderson, D.; Koch, T. Synth.
Commun. 1981, 11, 447.

2260 J . Org. Chem., Vol. 65, No. 7, 2000
Notes
blue solid (43% yield). R×a6 ) 0.82 (95:5 CHCl3/MeOH), UV-vis
(CHCl3) 669.6, and 607.6 nm, high-resolution mass spectral
analysis (FAB) MI 1772.64 (calcd mass for C104H97N8O16Co )
1772.64). Copper phthalocyanine 1 was obtained as a green solid
(48% yield). R×a6 ) 0.82 (95:5 CHCl3/MeOH), UV-vis (CHCl3)
676.6 and 610.2 nm, high-resolution mass spectral analysis
(FAB) MI 1776.61 (calcd mass for C104H97N8O16Cu ) 1776.64).
Ack n ow led gm en t. This research was supported by
a grant from the National Science Foundation.
Su p p or tin g In for m a tion Ava ila ble: 1H NMR spectrum
of 13; 13C NMR spectra of 10-12 and 14. This material is
available free of charge via the Internet at http://pubs.acs.org.
J O9919254